Fuel system

ABSTRACT

A fuel system constructed to furnish gaseous fuel, rather than liquid fuel, to an internal combustion engine. The delivery system converts liquid fuel to its gaseous state by lowering the pressure on the surface of the liquid, thereby causing the liquid to boil thereby providing the vapor which is fed to a venturi and thence into the intake manifold.

United States Patent [72] Inventor Joseph 1 Bald in 2,957,759 10/ 1960 Jettinghoff 48/180 Route 4, Box 305-A-2, Waycross, Ga. 3,081,160 3/1963 Ensign 48/180 X 31501 3,171,467 3/1965 Featherston... 261/36.l [21] Appl. No. 4,509 3,227,427 1/1966 Wells et al 261/115 X [22] Filed Jan. 21,1970 3,279,770 10/1966 Parker, Jr 261/36.] [45] P n 1971 3,433,608 3/1969 Epifanio, Sr... 48/180 3,464,803 9/ 1 969 Kimberley 48/ 1 80 3,486,524 1211969 Brooks 261/72 X [54] FUEL SYSTEM 5 claims 3 Drawing Flam Primary ExammerMorns 0. folk Assistant Examiner-R. E. Serwm [52] US. Cl 48/180 R, Attorney arowdy and Neimark 48/180 C, 123/119, 261/70, 261/72, 261/119, 261/DIG. 38 [51] Int. Cl ...F02m 21/04 [50] Field of Search 48/180 M,

180 180 180 180 102 A, 103; 123/119; ABSTRACT: A fuel system constructed to furnish gaseous 1 15, 70 fuel, rather than liquid fuel, to an internal combustion engine. The delivery system converts liquid fuel to its gaseous state by [56] Reerences Cited lowering the pressure on the surface of the liquid, thereby UNITED STATES PATENTS causing the liquid to boil thereby providing the vapor which is 2,856,169 10/ 1958 Mustain 48/180 X fed to a venturi and thence into the intake manifold.

l I 26 I 30 /0 t 54 i- 1 l6 3 40 I 3 /9 /4 3a 1 I 34 r l a i i' I /2'o 2 /a 2 q; 44 5s 5 l m Y1 PATENTED ntcze an INVENTO FUEL SYSTEM The present invention relates to fuel systems and, more particularly, to a fuel system for internal combustion engines wherein gaseous fuel rather than liquid fuel is supplied to the engine.

It is widely known among those skilled in the art that while the conventional jet-type carburetor produces fair performance over a wide speed range of the engine, nevertheless, due to inefficient droplets of gasoline which are not converted to vapor, there is the disadvantage that much of the fuel is never converted into enough of a vapor to burn properly. As these larger droplets of fuel are unburned they cause unnecessary wear on the cylinder walls due to their tendency to wash of any oil film which should be present for proper lubrication of the cylinder.

Then, too, in spite of many improvements in jet carburetion during the course of the years, it still remains a most inefficient system. The needle valves and jet openings in the carburetor must be carefully adjusted for even acceptable operation, and often they are out of adjustment with the result that too much gasoline is sprayed into the engine. The engine then will be hard to start, will be easily flooded, and will get very poor mileage to the gallon of gasoline. An internal combustion engine requires an accurately computed mixture of gasoline vapor and air for proper operation, and the process of spraying liquid gasoline into an engine manifold often does not produce the proper mixture.

While others have previously contemplated the concept of feeding gasoline vapor directly to the intake manifold of an internal combustion engine, these prior attempts have not been entirely successful and have not been adopted. Thus the Smith U.S. Pat. No. 3,049,850 requires an outside source of heat, means to force air through the liquid fuel, including agitating means and a fuel pump; besides being very expensive because of the presence of heating means and air baffles, the device will operate efficiently only when the engine has reached its optimum operating temperature. The Williams U.S. Pat. No. 3,338,223 also depends on the passage of air through the liquid fuel, and no provision is made to control the quantity of fuel vapor mixed with incoming air. Epifanio et al. U.S. Pat. No. 2,844,364 require a conventional carburetor or mechanical fuel pump and the system provided is merely supplementary. Hidden U.S. Pat. No. 1,210,169 provides no effective regulation of vapor mixing with the circulating air current Still other devices have other defects in operation and/or expense.

However, the present invention overcomes the above-mentioned shortcomings and weaknesses of the prior art devices and discloses a fuel system which is outstandingly effective and highly efficient. The liquid gasoline is vaporized into a highly combustible vapor which is then mixed with the necessary amount of air, in a venturi section, and this mixture is ulti mately fed directly into the internal combustion engine manifold. There is no excess of unvaporized liquid gasoline to cause poor operation and damage to the automobile, the device has a minimum of moving parts, the carburetor and fuel pump have been eliminated, and the system provides greater fuel economy than other known systems.

A general object of the invention is the provision of a fuel system which 'fumishes gaseous fuel to internal combustion engines and which overcomes the defects of the prior art, such as indicated above. Another object of the invention is the provision of a fuel system which eliminates the carburetor and fuel pump.

Still another object of the invention is the provision of a fuel system which has a minimum of moving parts, and which reduces maintenance.

Yet another object of the invention is the provision of a fuel system which produces a highly combustible vapor whereby there will be no appreciable waste of fuel nor unnecessary wear of the engine due to unburned fuel particles.

Still another object of the invention is the provision of a fuel system which, due to its simplicity of design, can be easily and economically manufactured and maintained.

Other objects and many of the attendant advantages of the invention will readily be appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein:

FIG. 1 shows an elevation view of the invention;

FIG. 2 is a view taken along line 2-2 of FIG. 1;

FIG. 3 is a view taken along line 3 3 of HO. 1.

Referring now to the drawings there is shown in FIG. 1, which represents a preferred embodiment of the invention, a vacuum chamber 10 having a top cover 11 which is secured to the chamber 10 by means of screws 12 or other suitable connections. A gasket, not shown, is placed between chamber 10 and cover 11, to insure an airtight fit, while chamber 10 may be made of any easily cast metal, such as steel, bronze or aluminum, or other material with sufficient strength to resist the crushing effect of outside atmosphere while the inside is under vacuum. While FIGS. 1 and 2 show the chamber 10 as being cylindrical, it is to be understood that its shape may be modified to fit existing conditions without altering the concept of the invention.

Attached to the side of vacuum chamber 10 by a suitable fitting is a liquid fuel line 14 which is connected to a gasoline supply tank (not shown), for supplying fuel to the vacuum chamber, and ultimately to the internal combustion engine. On the inside of the vacuum chamber 10, and connecting with the fuel line 14, there is a valve 16 having a sliding piston or needle 18 that cooperates with a small circular hole or recess 19 to cut off the flow of fuel through fuel line 14, The sliding piston 18 is actuated by a float 20 which is pivotally suspended at one end by a pin 22 mounted on the sidewall of the vacuum chamber 10. Float 20, piston 18, and recess 19 function together to maintain fuel in the chamber at a level shown at 24.

Passing through the cover 11 of vacuum chamber 10, and held in a tight connection by gland nut 26 or other suitable means, there is a connecting tube 28, which may be of any material that can resist crushing when under a vacuum. Connecting tube 28 passes through a gland nut 30 where it is held in a tight connection with a delivery tube 32. Delivery tube 32, which forms a passage for the gaseous vapors to the internal combustion engine, is fastened to the large end of a venturi 38. This connection between the delivery tube and the venturi is preferably accomplished by means of projections 34 which are an integral part of the delivery tube 32 and which extend outwardly, transversely to the longitudinal axis of the tube. Screws 36 extend through projections 34 and into the venturi, while a gasket (not shown) is placed between the two to insure an airtight fit. 7

The venturi 38 has elongated, inwardly converging side members or a frustoconical wall, which converge towards the delivery tube 32 until there is formed a narrow passage 50 between the sides of the venturi and the delivery tube, as the venturi and delivery tube pass through an adapter plate 48 which is used to attach these components to the intake manifold of the engine. Passage 50 forms an air passage for admitting an adjustable amount of air to be mixed with the gaseous vapor as the latter enters the engine intake, as will be more fully described below.

Located transversely across the bore of delivery tube 32 there is a butterfly valve 54 which is operated by a crank arm 52 to open and close the valve and thereby control the amount of gaseous vapor being supplied to the engine. Crack arm 52 is connected by suitable mechanical linkage (not shown) to the accelerator pedal of an automobile if the invention is being applied to a car engine, or to any other accelerator control should the invention be applied to any other internal combustion engine.

In order to provide an adjustable air supply to the system there is provided, around the large end of the venturi, an airmixing valve 42, which takes the configuration of a circular collar that can be rotated relative to, and around the neck of,

the venturi. There are provided a plurality of spaced holes 40 drilled around the periphery of the venturi walls, and a like number of holes 43 drilled in the air-mixing valve 42. Rotational adjustment of valve 42 so that holes 40 and 43 line up, or become misaligned, determines the amount of air being admitted by the venturi for mixing with the gaseous vapor. Valve 42 is connected to the engine accelerator by mechanical means (not shown) so that the volume of air being admitted into the engine is constantly varied depending on the speed of the engine. In its closed position the valve acts as a choke by shutting off all of the air supply.

Below the valve 42, and also encircling the neck of the venturi, there is an adjusting collar 44. Collar 44 and the venturi body have matching threads 46 for the correct positioning of valve 42, and a setscrew 56 is provided for locking collar 44 in place and preventing its movement when valve 42 is in correct axial position.

Turning now to the operation of the device, it can be seen that the system disclosed consists of three basic parts; (1) the vacuum chamber (2) the delivery tube 32; and (3) the venturi 38. The operation of the system is based on the fact that a fuel must be converted into a gas before ignition will occur. The present fuel delivery system is designed to change liquid fuel into its gaseous state before introducing it with the mixing air in the venturi. This is accomplished by lowering the pressure on the surface of the confined liquid fuel. Lowering the pressure causes the liquid fuel to boil and changes the top layer of molecules from the liquid to the gaseous state. This action takes place in vacuum chamber 10.

The vacuum chamber 10 is directly connected to the intake manifold by means of the delivery tube 32 and the venturi 38. The venturi 38 has the arrangement of valves 42 covering its ports or openings 40 and this arrangement is used to control the amount of outside air entering the system. Valve 42 is completely closed when starting a cold engine because of the choke; the system is not evacuated at this point, but is at the pressure of the surrounding atmosphere.

As the pistons of the engine begin their intake stroke they act as a vacuum pump by drawing in gases to fill the volume created by their downward movement. At this point the only available gas, mostly air, is that confined in the vacuum chamber 10. As the piston continues its downward movement vapor from the liquid fuel begins to fill the vacuum created by the withdrawn gas. in this way the cycle begins. As the engine accelerates the movement of the pistons is much faster, thus creating a stronger vacuum over the liquid fuel. In order to fill this evacuated space the liquid begins to boil and the gaseous fuel flows from the vacuum chamber 10 through the connecting tube 28 through the delivery tube 32 to the intake manifold and finally into the cylinders themselves. Valve 42 over the venturi ports 40 is now opened to admit outsid v air into the system in order to obtain the best fuel-to-air mixture. The butterfly valve 54 is installed in delivery tube 32 to regulate the amount of fuel supplied to the engine. The movement of butterfly valve 54 and air-mixing valve 42 must be correlated to obtain optimum engine performance.

The air entering the system through valve holes 43, and venturi ports 40, accelerates as it approaches the throat of the venturi and passes through passage 50. At this point the air passes the open end ofdelivery tube 32. (The delivery tube extends longitudinally into the venturi with its delivery end in the throat of the venturi, as at the adapter plate 48.) As this highvelocity air passes around the open end of the delivery tube it further reduces the pressure in the connecting tube 28 and vacuum chamber 10 and thereby assists in maintaining a vacuum over the surface of the liquid fuel. Should there be a need for additional heat to increase the rate of evaporation of the fuel, outside sources such as a hot water coil, an electric heating coil, or hot air could be directed around the bottom of the vacuum chamber.

As the engine operates, the fuel level inside the vacuum chamber is lowered due to the boiling of the liquid. In order to maintain the liquid level 24, a float 20 and valve 16 arran ement is installed in the vacuum chamber 10, and as the uel level lowers, float 20 pivots about its mounting pin 22 causing piston 18 to move downwardly and uncover opening 19 in fuel supply line 14, connecting with a conventional fuel tank. As piston 18 uncovers opening 19 fuel is forced into the vacuum chamber by the atmospheric pressure exerted on the surface of the liquid fuel in the main tank. As the level of the fuel rises, float 20 rotates clockwise about its pivot 22 forcing piston 18 upward to close off opening 19 in the fuel line. Since the fuel is consumed the cycle repeats itself as long as the engine is running.

It should be understood, of course, that as with any fuel system, the sizes and shapes of the individual parts will be dictated by the size and type of equipment on which it is to operate.

From the above description of the structure and operation of the invention it is obvious that there is disclosed a fuel system which provides many improvements over prior known systems. The simplicity of the present system with its minimum of moving parts and greater economy of fuel consumption will replace both the carburetor and fuel pump from a conventionally operated engine. The system will also work with the venturi in any position, and having only three simple valves, the device requires only a minimum of maintenance.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. lt is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A fuel system for supplying gaseous vapor to be burned in an internal combustion engine comprising;

a closed evaporating chamber;

means for maintaining a substantially constant level of vaporizable fuel in said chamber;

a delivery tube means communicating between said evaporating chamber and the intake manifold of the engine for effecting a vacuum in said chamber and for vaporizing fuel therein, said delivery tube means conducting the gaseous vapor to the intake manifold of the engine;

air inlet means associated with said delivery tube means, said air inlet means defining a venturi with said delivery tube means being coupled to said air inlet means at a relatively low-pressure area in the throat of said venturi;

first valve means associated with the large end of said venturi for regulating air input to the large end of said venturi for regulating air input to the system; and

second valve means associated with said delivery tube means for regulating gaseous fuel vapor input to the system, said first and second valve means being operatively interlinked.

2. The fuel system of claim 6 wherein the means to maintain a pool of liquid vaporizable fuel in the evaporating chamber is a float and needle valve connected to a fuel supply line.

3. The fuel system of claim 2 wherein the valve means has a plurality of holes which mate with like holes in the venturi.

4. The fuel system of claim 3 further including a butterfly valve located in the delivery tube for regulating the flow of gaseous vapor through the tube.

5. The fuel system of claim 4 wherein the valve means and the butterfly valve are mechanically coupled to the engine accelerator. 

2. The fuel system of claim 6 wherein the means to maintain a pool of liquid vaporizable fuel in the evaporating chamber is a float and needle valve connected to a fuel supply line.
 3. The fuel system of claim 2 wherein the valve means has a plurality of holes which mate with like holes in the venturi.
 4. The fuel system of claim 3 further including a butterfly valve located in the delivery tube for regulating the flow of gaseous vapor through the tube.
 5. The fuel system of claim 4 wherein the valve means and the butterfly valve are mechanically coupled to the engine accelerator. 